Advance custom fields gallery issue

I am using advance custom fields and I am not getting the gallery images. I tried everything but doesn't work. Please help me out.

<?php
$images = get_field('gallery');
if( $images ): ?>
    <div class="broast-gallery">
        <?php foreach( $images as $image_id ): ?>
            <div class="broast-image">
                <?php echo wp_get_attachment_image( $image_id, $size ); ?>
            </div>
        <?php endforeach; ?>
    </div>
<?php endif; ?>